The present invention is related to a device for quantifying athletic ability. The present invention is more specifically related to a device for measuring vertical leap ability of an athlete and the power generated with the vertical leap.
Athletes, and their coaches, are constantly striving to improve performance in their particular event. A critical part of this constant improvement is the ability to accurately and repeatable quantify various aspects of an athletes abilities.
One particular measurement which translates to ability in various sporting events is the standing vertical jump test. This test measures an athletes ability to jump from a standing position to the highest achievable height and relates to the power output of the athlete making the jump. Many devices are available which measure either the height reached or the elapsed time from leaving the surface to returning to the surface.
Devices which measure the highest point reached are legion in number as represented by U.S. Pat. Nos. 5,072,931; 4,208,050; 4,323,234; and 4,932,137. Each of these devices provide the athlete, or coach, with a quantitative measurement of the maximum height obtained. The maximum height is recorded without regard for jumping technique, weight, or other parameters which are critical to the evaluation of the power output of an athlete. For example, one athlete may jump from an upright position which would be indicative of the height obtained from a responsive jump in basketball, for example. A second athlete may squat and jump which is more indicative of a planned jump as in volleyball, for example. In each case the ability of the athlete may be reported very differently and the actual power of the athlete is not retrievable with the measurement technique. The height obtained is also dependent on other parameters which do not measure actual power such as the ability to reach for an object at the zenith of the jump. An athlete using maximum arm mechanics to enhance the jump may be less able to insure that the touch board, or equivalent, is contacted at the maximum height of the jump. The devices which measure height are useful but still lacking in their ability to fully determine an athletes ability.
Devices which measure elapsed time between leaving the surface and returning to the surface are also legion in number with representative examples being described in U.S. Pat. Nos. 5,897,457 and 5,838,638. These devices rely on a mathematical equation relating height obtained to jump time which is: EQU h=g (I/2).sup.2 /2
wherein h is height obtained in inches, g is the standard acceleration due to gravity (384 inches/sec..sup.2) and I is the time interval in seconds. This measurement is also dependent on technique since an athlete which lands in a crouched position may achieve a longer elapsed time than one which lands more upright even for the same height achieved if measured at the abdomen, for example. Therefore, the measurement does not necessarily evaluate actual height jumped, vertical displacement or power output.